title: Substrate ectodomain is critical for substrate preference and inhibition of γ-secretase.
abstract: Understanding the substrate recognition mechanism of γ-secretase is a key step for establishing substrate-specific inhibition of amyloid β-protein (Aβ) production. However, it is widely believed that γ-secretase is a promiscuous protease and that its substrate-specific inhibition is elusive. Here we show that γ-secretase distinguishes the ectodomain length of substrates and preferentially captures and cleaves substrates containing a short ectodomain. We also show that a subset of peptides containing the CDCYCxxxxCxCxSC motif binds to the amino terminus of C99 and inhibits Aβ production in a substrate-specific manner. Interestingly, these peptides suppress β-secretase-dependent cleavage of APP, but not that of sialyltransferase 1. Most importantly, intraperitoneal administration of peptides into mice results in a significant reduction in cerebral Aβ levels. This report provides direct evidence of the substrate preference of γ-secretase and its mechanism. Our results demonstrate that the ectodomain of C99 is a potent target for substrate-specific anti-Aβ therapeutics to combat Alzheimer's disease.
authors.affiliation: 1] Department of Neuropathology, Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0394, Japan [2] Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0076, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Funamoto
authors.forename: Toru
authors.initials: T
authors.lastname: Sasaki
authors.forename: Seiko
authors.initials: S
authors.lastname: Ishihara
authors.forename: Mika
authors.initials: M
authors.lastname: Nobuhara
authors.forename: Masaki
authors.initials: M
authors.lastname: Nakano
authors.forename: Miho
authors.initials: M
authors.lastname: Watanabe-Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Saito
authors.forename: Nobuto
authors.initials: N
authors.lastname: Kakuda
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Miyasaka
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Takaomi C
authors.initials: TC
authors.lastname: Saido
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ihara
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D000595:Amino Acid Sequence; D053829:Amyloid Precursor Protein Secretases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry* / Q000235:genetics; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D016466:CHO Cells; D003412:Cricetulus; D015870:Gene Expression; D057809:HEK293 Cells; D006801:Humans; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
chemical_list: D053829:Amyloid Precursor Protein Secretases; D016564:Amyloid beta-Protein Precursor; D015703:Antigens, CD; D010455:Peptides; D011994:Recombinant Proteins; D012799:Sialyltransferases; C545487:APP protein, human; C093493:ST6GAL1 protein, human; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase